New experiments with BEC in an optical lattice

Summary form only given. Our new Rb BEC apparatus features a magnetic transport scheme, good optical access and maximum flexibility. This allows for new experiments which investigate the interaction of a BEC in various environments. Our first experiments will study BEC in a 1D optical lattice. We construct and characterize a coherent accelerator for a condensate which consists of a far detuned standing light wave. We load the BEC adiabatically into the lattice ground state and accelerate the lattice by frequency chirping the lattice laser beams. In simple words the accelerated lattice drags the condensate with it. Coherent acceleration to velocities corresponding to 10 photon recoils has been demonstrated recently in a similar setup. We test whether this scheme can be extended to transport BEC over distances of tens of centimeters. In order to represent a valuable new tool the accelerator has to be able to coherently transfer about 1000 photon recoils (recoil velocity of ⁸⁷Rb = 5.85 mm/s) to the atoms in less than 100 ms. We test the efficiency of the transport and study atomic loss, heating and phase corrugation of the condensate wavefunction. In the near future we will extend our work to 3D optical lattices where we will use a Mott insulator state to study molecule formation out of atom number states.